On Sunday March 2, mike@xxxxxxxxxxxx wrote:
>
> So apparently it does switch to read-write on the first write
> request, but the rebuild is not continuing.
Yes.
This bug is fixed by the following patch which I have just sent of for
inclusion in mainline.
The patches talks about "reshape" but it applies to "resync" too.
The workaround is to "mdadm -w" before the first write.
Thanks,
NeilBrown
Make sure a reshape is started when device switches to read-write.
A resync/reshape/recovery thread will refuse to progress when the
array is marked read-only. So whenever it mark it not read-only, it
is important to wake up thread resync thread.
There is one place we didn't do this.
The problem manifests if the start_ro module parameters is set, and a
raid5 array that is in the middle of a reshape (restripe) is started.
The array will initially be semi-read-only (meaning it acts like it is
readonly until the first write). So the reshape will not proceed.
On the first write, the array will become read-write, but the reshape
will not be started, and there is no event which will ever restart
that thread.
Signed-off-by: Neil Brown <neilb@xxxxxxx>
### Diffstat output
./drivers/md/md.c | 1 +
1 file changed, 1 insertion(+)
diff .prev/drivers/md/md.c ./drivers/md/md.c
--- .prev/drivers/md/md.c 2008-02-22 15:46:25.000000000 +1100
+++ ./drivers/md/md.c 2008-02-22 15:46:52.000000000 +1100
@@ -5356,6 +5356,7 @@ void md_write_start(mddev_t *mddev, stru
mddev->ro = 0;
set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
md_wakeup_thread(mddev->thread);
+ md_wakeup_thread(mddev->sync_thread);
}
atomic_inc(&mddev->writes_pending);
if (mddev->in_sync) {
--
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